There is a known braking force holding control apparatus for holding a braking force when the vehicle is at a halt (PATENT LITERATURE 1). The apparatus disclosed in PATENT LITERATURE 1 has a filter for limiting changes of an output by an acceleration sensor for calculating a road surface gradient. In such a structure, it is possible to suppress changes of acceleration values due to pitching movement, which is a front-rear swing caused when the vehicle halts.
In addition, the vehicle braking force holding control apparatus determines a braking force to be held according to the filtered acceleration to stop the vehicle even on a slope.    PATENT LITERATURE 1: JP-A-2009-202665